Various methods have been proposed for improving security, particularly in connection with baggage and cargo to be shipped on domestic and international airline flights. Thus, everything from metal detectors to X-ray inspection of baggage and cargo to trained dog sniffing has been used in an attempt to prevent placement of explosive devices on airplanes.
When an explosive device ignites, attempts to locate the culprit involve inspection of debris from the aircraft in attempt to determine the type of device, the manufacturer and the purchaser. However, such information is often difficult and time consuming to obtain, thus giving the culprit significant time to go into hiding.